Portable tool box



FIG. 1 is a front perspective view of a new design for a portable tool box, with the handle at a folded position;

FIG. 2 is a front view of a new design for a portable tool box as seen in FIG. 1;

FIG. 3 is a rear view of a new design for a portable tool box, showing the handle at a folded position, as seen in FIG. 1;

FIG. 4 is a left side view of a new design for a portable tool box, showing the handle at a folded position, as seen in FIG. 1; right side view being a mirror image; and,

FIG. 5 is a top view of a new design for a portable tool box, showing the handle at a folded position, as seen in FIG. 1.

The broken lines illustrate portions of the portable tool box and form no part of the claimed design. 

CLAIM The ornamental design for a portable tool box, as shown and described. 